Effect of pulsed electric fields on the structure of bovine α-lactalbumin

Pulsed electric field (PEF) processing is a non-thermal method of food preservation that uses short bursts of electricity for enzyme and microbial inactivation causing minimal effect on food quality. The purpose of this work was to apply PEF to induce structural changes in bovine α-lactalbumin (α-LA).The treatments were performed in an electroporator with field intensities of 4.5, 9 and110okV/cm, using 2,4 and 10 square wave pulses and a 0.2 Hz frequency. Changes were evaluated in PEF-treated protein solutions buffered at pH values of 3, 7 and 10. ANS fluorescence analysis indicated that the higher the field intensity and number of pulses, the higher the protein hydrophobicity. PEF induced moderate changes in the protein secondary and tertiary structure as determined by circular dichroism. These results indicate that PEF can induce non-denaturing changes in the structure of proteins such as α-LA with the possibility of generating beneficial changes in their functional properties for specific food uses.